Craftech’s Plastic Fasteners Used in New Fish Farming Technology

When Ray Lawrence, Production Manager at Ocean Farm Technologies, Inc., got a call from a customer in Mexico he knew he needed to act quickly. Ocean Farm Technologies is the developer of the Aquapod™, a fish farming containment system. The company installs Aquapods™ around the world. The Aquapod™ is constructed of individual triangle net panels fastened together in a spheroid shape. Each pod has 200 individual panels or more. Ocean Farm Technologies can modify the netting to be appropriate for many different sizes of fish, including even shrimp.

The individual panels installed in the structure can be modified to accommodate functions such as access, feeding, fish transfer, grading, and harvesting.

The Aquapod™ was designed to serve as a secure containment system for fish in the open sea. It is designed to resist strong sea weather while fully or partially submerged. The company has customers around the world in both the private and the governmental sectors.

Lawrence knew he needed to act quickly when he got the call from Mexico because transferring fish into an Aquapod™ is a time-sensitive task. The fish in question, the Totoaba, is raised in hatcheries on-shore and then transferred to an off-shore Aquapod™ when they are large enough. This transfer is time-sensitive. The endangerment of the Totoaba due to over-fishing caused the Mexican government to ban commercial fishing of the fish in 1975. Since then, the Totoaba has become popular in the fish farming industry.

Ocean Farm Technologies originally designed the Aquapod™ using galvanized steel. As we’ve described previously in the blog, all metals rust when exposed to water. Steel also has difficulty resisting the saltwater and UV rays present in the Aquapod’s™ marine environments. After some experimentation with high performance plastics such as Delrin® and nylon, the company switched to thermoplastic polyurethane (TPU) parts and hasn’t looked back. TPU is one of the strongest high performance plastics with a tensile strength of 29,977 PSI or 186 MPa. It is resistant to a variety of chemicals and environmental hazards including the salt water and UV rays present in marine environments. TPU also has very low water absorption, making it able to withstand being submerged in water for long periods. In the original model of the Aquapod™, the steel fixtures would corrode over time. The corrosion made it difficult to remove any of the pod’s panels for repair. Technicians would have to cut into the corroded steel, a difficult task when working under water. TPU fasteners are easily removed with wrenches even after many years spent underwater, making repairs much easier and more cost effective.

Craftech currently manufactures vinyl ester rod and a variety of TPU fasteners for use in the Aquapod™. The vinyl ester rod is used in the frame of the pod. Once the frame has been constructed, Ocean Farm Technologies uses Craftech’s TPU hardware to fasten the structure together. Lawrence’s customer in Mexico had an older Aquapod™ model that had steel fixtures. The Ocean Farm Technologies team needed to be able to quickly replace the steel parts with plastic ones before the fish in the hatchery grew too large to be moved. After Lawrence’s urgent call to Craftech, Craftech’s production team was able to ship over 13,000 rods and fasteners within seven business days. This express shipment allowed Ocean Farm Technologies to update the Mexican Aquapod™ in time.

Have you ever considered replacing your metal fasteners with plastic? Check out all of Craftech’s products online!